Steched cover image in mobile

[simiform]

Is there a way to customize the way the cover image is displayed? It currently stretches the image for thin displays (mobile). Most modern ebook readers use object-fit: contain. I couldn't find anything about images in defautl.js. Not a huge deal, but it looks bad in mobile when users open the ebook. It only seems to have this issue on the cover, not images within the book.

Thank you for keeping this up—I'm not sure why there aren't more epub readers for website design.